After a night in the jungle that I would rather not talk about, I have discovered what I think may be the perfect solution to my problem! After wandering around all day yesterday, making cuts in every tree trunk I came across, it was barely two hours today when I struck it lucky and thin white sap immediately began to ooze out of one, which I am almost certain is a rubber tree, judging also by its leaf shape. I have bored a small hole and stuck in a sliced hollow reed-stem, which seems to be working to direct the dripping liquid into my half-coconut shell. I am extremely hopeful that this will prove to be rubber latex.
I have sacrificed one of my lavalavas and torn it into strips to mark the path back to this tree. Hopefully by tomorrow I will have enough to repair my dugout. It's good to be back at the beach tonight. The weather is unsettled and windy but warm.